Currently, intestinal inflammation is monitored through disclosure of patient symptoms, endoscopy with histology, and other radiological imaging methods, such as ultrasound and CT scans. Recently, several groups have proposed the use of fecal matter to measure levels of neutrophil-granular proteins released from activated neutrophils, such as lactofenin, calprotectin, and polymorphonuclear neutrophil elastase via ELISA (enzyme-linked immunosorbent assay), which correlated to endoscopic presence and severity of inflammation. In addition to fecal proteins, serum levels of C-reactive protein (CRP) have been measured as indicators of intestinal inflammation.
Accuracy of inflammatory activity is hindered, however, by the biased nature of symptom reports by patients, as well as by inconsistent findings with the use of fecal proteins as indicators of inflammation. Although these fecal proteins are able to differentiate active versus inactive disease, none of these markers are consistently superior to reflect inflammation confirmed by endoscopy, and CRP has a very low diagnostic accuracy. These fecal and serum markers have therefore been suggested to be used in combination with symptom disclosure to accurately diagnose intestinal inflammation.
There is a need to identify improved markers for inflammatory disease. There is also a need for methods of detecting subclinical inflammation.